common: Drop log.h from common header

Move this header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mmc/mmc_spi.c b/drivers/mmc/mmc_spi.c
index c693fb2..0b690ec 100644
--- a/drivers/mmc/mmc_spi.c
+++ b/drivers/mmc/mmc_spi.c
@@ -8,6 +8,7 @@
  */
 #include <common.h>
 #include <errno.h>
+#include <log.h>
 #include <malloc.h>
 #include <part.h>
 #include <mmc.h>